Dyeing of polypropylene with dyes of the benzeneazo pyrazolone series



United States Patent ABSTRACT OF THE DISCLOSURE Dyeing and printing of polypropylene textile materials such as textiles and yarns thereof wherein the polypropylene contains a chelating metal and is dyed or printed with a dye of the benzeneazo pyrazolone series.

This invention relates to dyeing, including printing, of polypropylene textile materials with monoazo dyes of the benzeneazo pyrazolone series, which are outstandingly suitable for this purpose.

It is known that the dyeing and printing of polypropylene textile materials with disperse dyes oifers great difficulty because most disperse dyes, particularly monoazo dyes which are suitable for dyeing hydrophobic fibers, for example fibers of acetate silk and polyesters, do not give dyeings having satisfactory fastnesses, particularly sublimation and solvent resistance, on polypropylene. Another deficiency is the low afiinity of many disperse dyes for nonmodified polypropylene. Many research workers have therefore developed fibers containing additives for increasing dyeability, as may be seen from numerous literature references. ISuch fibers containing additives for increasing dyeability are above all those compositions which contain metal compounds in small amounts, particularly oxides, salts, or chelate complexes of Zinc, aluminum, iron, chromium, cobalt, or nickel. These metals can form chelates 'with chelatable dyes and are therefore referred to below as chelatable metals.

Polypropylene containing metal compounds of the said type may contain these compounds as catalyst residues from the production of the polymer. The metal compounds may also have been added to the polypropylene to stabilize it against oxidizing influences, exposure to light and thermal stress, or to improve the dyeability of the polypropylene. Polypropylene of this type contains advantageously more than 0.01% by weight, for example 0.1% by weight, of chelatable metal. When dyeing this metal-modified polypropylene with dyes capable of forming chelates fast dyeings can be obtained. These dyeings are, however, rather dull and improvement of the light fastness is desirable. Furthermore pure yellow shades cannot be obtained with chelate forming dyes.

It is therefore an object of the invention to provide improvements wherein polypropylene containing a chelatable metal is dyed or printed in deep and extremely lightfast shades. A further object is to dye polypropylene bright yellow shades which are also fast to washing and drycleaning, the term dyeing being intended to include print- These objects are achieved with dyes of the formula in which R denotes an unsubstituted or substituted alkyl Patented Mar. 3, 1970 or aryl radical, R denotes an unsubstituted or substituted aryl radical, and the ring A may bear non-ionic substituents, such as halogen atoms or alkyl, alkoxy, dialkylamino or aroylamino groups. Phenyl radicals are preferred as aryl radicals. These dyes are obtained in the usual way by diazotizing an amine having the Formula II:

and coupling with a compound having the Formula III:

CN-R 1 HZN (III) in which R R and A have the above meanings.

Dyes of the Formula I which are preferred for dyeing or printing of polypropylene textile materials are those having the formula wherein R represents phenyl, p-chlorophenyl or particularly methyl and ethyl, R represents phenyl, p-methylphenyl or p-methoxyphenyl, R represents hydrogen, methoxy, ethoxy, methyl, chloro or diethylamino and R represents hydrogen or benzoylamino.

Examples of specific diazo components II are:

l-amino-2-methoxybenzene, l-amino-Z-ethoxybenzene, 1-amino-2-methoxy-5-methylbenzene, l-amino-2-methoxy-S-chlorobenzene, 1-amino-2,4-dimethoxybenzene, 1-amino-2,5-dimethoxybenzene, 1-a-mino-2,5 -diethoxybenzene, l-amino-2-ethoxy-4-diethylaminobenzene, l-amino-2,5-dimethoxy-4-chlorobenzene, 1-amino-2,4-dimethoxy-S-chlorobenzene, 1-amino-2-methoxy-5-methyl-4-benzoylaminob enzene, 2-amino-4-chlorodiphenylether, and 2-amino-4,4'-dichlorodiphenyl ether.

Examples of coupling components having the Formula III are:

1-pheny1-3-irnino-5-oxopyrazolidine, 1-p-tolyl-3-imino-5-oxopyrazolidine,

1- (4'-chlorophenyl) -3 -imino-5-oxopyrazolidine, and l- (4-methoxyphenyl -3-imino-5-oxopyrazolidine.

The preparation of these compounds is known from Ben, 39 (1906) 22/82 and J. Amer. Chem. Soc, 66 (1944) 1.

The nomenclature imino-oxopyrazolidine used above is equivalent to amino-pyrazolone or amino-hydroxypyrazole since the above compounds and the dyes according to the invention can probably exist in tautomeric forms. Therefore, the compound is thesame whether it is designated by one of the structures The diazo coupling of the diazotized amino compounds having the Formula II with the compounds having the Formula III is carried out in conventional manner, preferably in buffered aqueous solution. The water-insoluble products are thus deposited.

The dyes of Formula I, after having been brought in conventional manner into a finely divided form by grinding with a dispersing agent, are suitable for dyeing and printing hydrophobic synthetic fibers and, as indicated above, for dyeing and printing polypropylene textile materials containing metal compounds in small amounts, particularly oxides, salts or chelate complexes of zinc, aluminum, chromium, cobalt, iron or preferably nickel.

Polypropylene fibers are dyed with the dyes according to this invention by the conventional methods for dyeing with disperse dyes. Water-insoluble dyes are used in the form of aqueous dispersions obtained in conventional manner. A high degree of fine dispersion of the dye is very desirable vwith a view to achieving a good dye yield.

It is possible to dye from a long liquor or, by impregnation, with a short liquor on a padding machine with the dyes obtainable according to the invention. It is advantageous to dye at 70 to 130 0., preferably at 90 to 130 C., from a long liquor. If the material to be dyed is impregnated on a padding machine, this may be done for example at room temperature or slightly elevated temperature and the impregnated material may be heated for a short time at about 130 C. after it has been dried at 70 to 100 C.

It is advantageous to dye in the neutral or weakly acid range; adjusting the pH value to 4 to 5 by adding acetic acid increases the dye yield in many cases.

In some cases it is advantageous to add to the dye liquor, in addition to the dispersing agent already present in the dye formulation, a further dispersing or emulsifying agent, for example naphthalene sulphonic acid-formaldehyde condensation products, fatty acid ethenoxyla tion products, ethenoxylation products of aliphatic amines or alcohols or polyglycol ethers, also in sulphonated form.

Polypropylene textile material may also be printed with the dyes of Formula I. Conventional thickeners, such as methyl cellulose, carob bean flour, industrial gum, alginates or tragacanth, are used for the preparation of the print pastes. The print pastes may also contain other conventional additives, such as urea or thiourea, and substances which facilitate application of insoluble dyes to textile fibers, such as thiodiglycol or sulphonated oils.

The print colors are applied to the textile material in a conventional manner, for example by screen printing or roller printing. The prints are then dried and the textile material is treated either with steam at atmospheric pressure or superatmospheric pressure or the printed textile material is treated with'hot air at 110 to 130 C.

The dyed or printed textile material of metal-containing polypropylene may then be given a conventional aftertreatment, such as by washing, brightening, decatizing or heat setting.

All thermal treatments should be carried out at a temperature belowthe softening point of polypropylene.

The dyed or printed textile material contains the dyes in suflicient amounts to produce light to deep shades. As a rule the dyes are incorporated in an amount of 0.1 to 1% by weight, calculated as non-formulated dye, with reference to the textile material.

Dyeings and prints obtained with dyes according to the invention have very high light fastness and high fastness to washing and dry-cleaning.

The following examples will further illustrate the invention. The parts and percentages specified in the examples for production of and use of the dyes are by weight.

(A) PRODUCTION OF DYES Example 1 123 parts of l-amino-Z-methoxyaniline is dissolved cold in 2500 parts of water and 250 parts of 10 N hydrochloric acid. 1500 parts of ice is added to the solution and the amine is diazotized with a solution of 69 parts of sodium nitrite in 500 parts of water. The mixture is stirred for another two hours and the excess of nitrite is then destroyed with aminosulphonic acid. The diazo solution is then slowly stirred into a solution of parts of 1 phenyl 3 imino 5 oxopyrazolidine in 1500 parts of water, 40 parts of sodium hydroxide and 50 parts of sodium acetate. When coupling is over, the deposited dye is filtered off, washed with water and dried. 290 parts of a dye having the formula:

N=N-O/ I HzN-C=N is obtained.

The following dyes are obtained in the same way:

Example 2 002m HO Q Example 3 (|)CH2 HO G -tu -N (3H3 HzN Example 4 OCHa HO Cl HzN Example 5 OCHs HO N=N- N CH3 HzN Example 6 OCzHs HO Q N=N I I N )C2H5 HzN Example 7 C 2115) 2N N=N I HzN Example 8 OCH; HO

N=N l I N HzN Example 9 (B) DYEING AND PRINTING OF POLYPROPYLENE Example (a) 100 parts of a yarn of polypropylene containing nickel is dyed in a liquor containing, in 4000 parts of water, 0.5 part of the finely divided azo dye of Example 5, 1 part of the product obtainable by reaction of 1 mole of sperm oil alcohol with 80 moles of ethylene oxide followed by sulfation, and 3 parts of 30% aqueous acetic acid. The dye liquor is brought from 70 to 100 C. during the course of fifteen minutes, dyeing is continued for ninety minutes at boiling temperature and the yarn then rinsed and dried. A full yellow dyeing is obtained which is distinguished by very good light, wash and solvent fastness.

(b) 100 parts of a knitted fabric of polypropylene containing nickel is treated in a liquor containing, in 3000 parts of water, 0.3 parts of the finely divided azo dye of Example 1 and 0.5 part of a reaction product of naphthalenesulfonic acid and formaldehyde for one hour in a high-temperature dyeing apparatus at 130 C. A clear greenish yellow dyeing is obtained having excellent light fastness and very good wash and solvent fastness.

(c) A cloth of polypropylene containing nickel is printed with a print paste having the following composition:

Parts Finely divided azo dye of Example 3 10 Thiodiglycol 50 Thickener based on carob bean flour (1:2) 500 Water 440 The cloth is dried and the dye is fixed either by heating the cloth for five minutes at 130 C. or by steaming for fifteen minutes at 1.5 atmospheres gauge. The yellow print obtained is distinguished by outstanding fastness properties.

We claim:

1. A process for dying polypropylene textile material which comprises applying to said material a dye of the formula:

wherein R represents a member selected from the group consisting of methyl, etheyl, phenyl and p-chlorophenyl; R represents a member selected from the group consisting of phenyl, p-methylphenyl and p-methoxyphenyl; R represents a member selected from the group consisting of hydrogen, methoxy, ethoxy, methyl and diethylamino; and R represents a member selected from the group consisting of hydrogen, chloro and benzoylamino.

2. A process as claimed in claim 1 wherein said dye is a dye of the formula:

3. A process as claimed in claim 1 wherein said dye is a dye of the formula:

OCH3

contains a small amount of chelatable metal, said polypropylene bing dyed with a dye of the formula:

wherein R represents a member selected from the group consisting of methyl, ethyl, phenyl and p-chlorophenyl; R represents a member selected from the group consisting of phenyl, p-methylphenyl and p-methoxyphenyl; R represents a member selected from the group consisting of hydrogen, methoxy, ethoxy, methyl and diethylamino; and R represents a member selected from the group consisting of hydrogen, chloro and benzoylamino.

7. A textile material as claimed in claim 6 wherein said dye is a dye of the formula:

8. A textile material as claimed in claim 6 wherein said dye is a dye of the formula:

OCH:

9. A textile material as claimed in claim 6 wherein said dye is a dye of the formula:

References Cited FOREIGN PATENTS 992,561 5/ 1965 Great Britain.

NORMAN G. TORCHIN, Primary Examiner J. E. CALLAGHAN, Assistant Examiner US. Cl. X.R. 8-55 

